You guys probably know of the Patek Philippe 3970 and 5970 - they are the precursors to this year's 5270 Perpetual Calendar Chronograph. But do you know about the 5004? The 5004 was introduced in 1996 and is essentially a 3970 with a split-seconds chronograph. Simple enough, right? Well, this split-seconds perpetual calendar was so difficult to produce and so costly, Patek only made about 12 per year, and even stopped production at one point while working on a separate split-seconds caliber.

You guys probably know of the Patek Philippe 3970 and 5970 - they are the precursors to this year's 5270 Perpetual Calendar Chronograph. But do you know about the 5004? The 5004 was introduced in 1996 and is essentially a 3970 with a split-seconds chronograph. Simple enough, right? Well, this split-seconds perpetual calendar was so difficult to produce and so costly, Patek only made about 12 per year, and even stopped production at one point while working on a separate split-seconds caliber.

After just 15 short years, the Ref 5004 is being retired by Patek. To celebrate, they have created the last fifty of these uber-chronos to be made in stainless steel (all previous models were in precious metals) and sold exclusively at the Geneva Patek Philippe salon for a price of 270,000 CHF, or around $308,000 at the time of publishing. Patek Philippe themselves communicated no information about the watch, either.